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The effects of vegetarian diets on glycemia and lipid parameters in adult patients with overweight and obesity: a systematic review and meta-analysis

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Abstract

Several randomized controlled trials have reported the effects of vegetarian diets on blood lipids and glucose homeostasis in adults, but not in overweight or obese individuals. Thus, the purpose of this study was to evaluate the effects of vegetarian diets on blood lipids and glucose homeostasis in overweight or obese adults by systematic review and meta-analysis. We searched Medline, Embase, and the Cochrane Library through October 2021. We chose to include overweight or obese patients in the studies of the vegetarian diet for metabolic control. Seven trials with a total of 783 overweight or obese adult were included in the meta-analysis. The analysis of the data revealed that the vegetarian diets significantly reduced low-density lipoprotein cholesterol (LDL-C) (WMD, −0.31; 95% CI, −0.46 to −0.16), total cholesterol (TC) (WMD, −0.37; 95% CI, −0.52 to −0.22), and HbA1c (WMD (%), −0.33; 95% CI, −0.55 to −0.11). The vegetarian diets had an elevated effect on blood triglycerides (WMD, 0.29; 95% CI, 0.11–0.47). However, there were no significant effects of vegetarian diets on high-density lipoprotein cholesterol (HDLC), Fasting plasma glucose(FPG), and HOMA-IR in these individuals. The results of this study suggest that vegetarian diets effectively reduce LDL-C, TC, and HbA1c levels, thus functioning as a promising therapeutic strategy for improving the metabolic dysfunction in overweight or obese individuals. However, further large-scale clinical trials are required to confirm the validity of these findings.

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Data availability

Data reviewed and analyzed during this meta-analysis is available from the corresponding author upon reasonable request.

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Contributions

YX and CL conceptualized and designed the research study, performed initial statistical analyses, drafted the manuscript, approved the final manuscript as submitted, had full access to all the data in the study, and took responsibility for the integrity of the data and the accuracy of the data analysis; YX developed and implemented the systematic review search strategy, generating the initial search results; YX and YY independently reviewed study titles, abstracts, and full texts to determine included studies, performed data extraction, and evaluated each study for risk of bias; and YY and GLM assisted in refining the study design, reviewed and revised the manuscript, and approved the final manuscript as submitted.

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Correspondence to Chuan Li.

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Xu, Y., Mo, G., Yao, Y. et al. The effects of vegetarian diets on glycemia and lipid parameters in adult patients with overweight and obesity: a systematic review and meta-analysis. Eur J Clin Nutr (2023). https://doi.org/10.1038/s41430-023-01283-x

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